1. Field of the Invention
The invention relates to railroads generally, and more particularly to a method and system for automatically reporting faults in wayside devices.
2. Discussion of the Background
Train safety has long been a concern in the railroad industry. This concern has led to proposals for and development of automated, safety-enhancing systems including Cab Signaling Systems, Automatic Train Control Systems (ATC), and a Positive Train Control (PTC) System known as the TRAIN SENTINEL™ system available from the assignee of the present application, Quantum Engineering, Inc.
These automatic systems vary in their implementation. However, one aspect shared by several of these systems is the use of wayside devices that electronically transmit status information to either a train or a centralized train control authority such as a dispatcher. In some systems, the devices transmit the status information upon receiving an interrogation signal from an approaching train. In other systems, the devices include or are connected to some apparatus (e.g., a track circuit or radar detector) that detects the presence of an approaching train and transmit the status information when the oncoming train is detected. In yet other systems, the devices automatically transmit the status information continuously or periodically regardless of whether a train is approaching. Examples of such devices are wayside signals (which are used in system such as Automatic Block Signaling systems to inform a train as to how to proceed), switches, crossing gates, track occupancy circuits, broken rail detection circuits, avalanche detection circuits, and bridge/track alignment circuits. These devices generally include at least a transmitter to transmit the status information and, in cases where the devices respond to an interrogation signal, a transceiver. The transmitter or transceiver is often, but not necessarily, radio frequency. These devices may or may not include a visual indication (e.g., one or more color signal lights) of the status information. Such devices shall be referred to herein as “wayside status devices.”
Many of these systems depend upon the electronically-transmitted status information from wayside status devices rather than any visual indication of status. Furthermore, many of these systems are fail-safe in that some sort of special procedure must be performed in order for the train to pass a wayside status device if a “good” status information signal is not received from the wayside status device. For example, some versions of the TRAIN SENTINEL™ system will allow an engineer/operator to pass a switch at a very slow speed so that the engineer/operator can visually confirm that the switch is in the correct position when the electronically transmitted status information from the switch indicates that the switch is in the wrong position. Those of skill in the art will recognize that a wide range of other types of such special procedures are possible. However, regardless of the type of special procedure, it will invariably involve additional time, which increases cost.
Because of the importance of the electronically-transmitted status information in such systems, it is important that wayside status devices function properly. Hence, it is important that malfunctions in wayside status devices be reported as soon as possible so the malfunctions can be repaired as soon as possible to avoid wasting time.
What is needed is a method and apparatus that facilitates the report of malfunctioning wayside status devices.